Case 1: Drop due to missing neighbor
Problem: Detected Nighbor (DN)
UE sends a Measurement Report that contains an event1a means adding a new RL (cell) to Active Set
If the reported cell is not in the current neighbor cell list and the reported Ec/No is better than the best serving cell Ec/No in AS by some dBs (set by a RNC parameter)
If for any reason the new cell can not be added to AS, call will be released